629 ND cylinder gap? Cleaning, rub?

[Model29-26.5]

I shot my 629 For the first time at the range yesterday.
I shot 6 44 specials, then after one 44 mag there was a rub and the cylinder didn’t want to turn.
That was the only 44 I shot in it.
I took it home and gave it a good clean (I can’t remember if I had cleaned it well after I picked it up a few months ago) The cylinder turns fine now except for a very slight bit of resistance on one of the chambers.
Typically, in this situation, is it due to needing a clean or might there be other issues.
There is hardly any cylinder gap at all, and I know that there cannot be absolute zero gap.
I’m thinking of measuring the gap and possibly if necessary trimming the yoke a thou?
I can give it another good clean first.
Any suggestions??
Thanks

 

[Vtgw938]

Stretching the yoke tube or adding a shim would increase barrel gap if there is end shake there. First clean it good and than check for fore and aft moment in the yoke/frame area with no cylinder but yoke closed and than in the cylinder/yoke assembly with the cylinder installed. Measure barrel/cylinder gap and rear gap. Don't go cutting anything.

Make sure no shims have been added to the yoke where it goes into the frame. They can be hard to see and may be stuck on either the yoke or the frame. Shims here usually reduce the barrel gap.

 

[Pisgah]

Check the ejector rod and yoke. If either is slightly bent, you'll have the drag you've described.

 

[Protocall_Design]

You want a minimum of .006 if you are shooting any lead bullets, minimum of .004 if you shoot only jacketed. Make sure to clean the surfaces of extractor bottom and cylinder recess it sits in before doing any measurements.

It may be that the front face of the cylinder is at a slight angle. That will cause the cylinder gap to get wider and narrower as the cylinder rotates. The fix for that is to face it off square on a lathe. Sometimes the back of the barrel is not square either. There is a hand tool to fix that also.